LISBON (Reuters) - Portugal's parliament approved in the first reading on Wednesday the draft 2013 budget that brings about the biggest tax hikes in the country's modern democratic history, which the government says are needed to keep a 78-billion euro EU/IMF bailout afloat.

The two parties of the centre-right ruling coalition who have 132 seats in the 230 seat parliament voted for the bill. The remaining parties voted against, including the main opposition Socialists, whose previous administration requested the bailout in April 2011. There were no abstentions.

The bill, which includes tax hikes on income, property and a proposed new tax on financial transactions, will now be discussed in committees. The final vote is expected on November 27 but the broad guidelines are now approved.

The unpopular bill is still likely to be sent to the constitutional court for checks on whether the tax hikes are fair, after stirring opposition from professional bodies and many politicians, which means uncertainty will remain.

(Reporting By Andrei Khalip)